Cartilage removal tool and method

ABSTRACT

An instrument for use in cartilage removal comprises an elongate body having a first end and a longitudinal axis having a longitudinal direction. A cartilage removal portion is coupled to the elongate body at the first end. The cartilage removal portion includes a plurality of serrated blades substantially perpendicular to the longitudinal axis and adapted for removing material while moving in the longitudinal direction. Each serrated blade has a centroid located along the longitudinal axis.

FIELD

This disclosure pertains generally to medical devices, and particularlyto surgical tools for cutting and shaping tissue.

BACKGROUND

In a bone fusion procedure, a surgeon removes cartilage from a jointbetween two adjacent bones and then attaches an implant to both of thetwo adjacent bones. Proper cartilage removal allows subsequent bonegrowth between the two adjacent bones to take place. Cartilage removalmay be one of the most time-consuming and painstaking steps of a fusionprocedure. Cartilage removal has been performed using curettes,rongeurs, or a shaver in an arthroscopic system.

SUMMARY

In some embodiments, an instrument for use in cartilage removalcomprises an elongate body having a first end and a longitudinal axishaving a longitudinal direction. A cartilage removal portion is coupledto the elongate body at the first end. The cartilage removal portionincludes a plurality of serrated blades substantially perpendicular tothe longitudinal axis and adapted for removing material while moving inthe longitudinal direction. Each serrated blade has a centroid thereoflocated along the longitudinal axis.

In some embodiments, a method for cartilage removal comprises contactinga cartilage of a patient with a cartilage removal portion of a tool. Thecartilage removal portion has a first end, a second end, and alongitudinal axis extending therebetween. The cartilage removal portionincludes one or more elongate members disposed radially outward from thelongitudinal axis. The one or more elongate members extend parallel tothe longitudinal axis from the first end to the second end. The elongatebody rotates around the longitudinal axis or reciprocate, so that theone or more elongate extensions cut or abrade the cartilage.

In some embodiments, a method for cartilage removal comprises contactinga cartilage of a patient with a grater. The grater has a shank attachedto a plate. The plate has a first face and a second face opposite thefirst face. The plate defines one or more holes extending therethroughfrom the first face to the second face. Each hole is defined by arespective cutting edge of the plate. The plate reciprocates, so thatthe respective cutting edge defines one or more of the holes cuts orabrades the cartilage.

In some embodiments, a method for cartilage removal comprises contactinga cartilage of a patient with a cartilage removal tool having a centrallongitudinal axis, and at least one rotatable helical strip arrangedaround the longitudinal axis. The helical strip is separated radiallyfrom the longitudinal axis by a space. The at least one helical strip isrotated so that the at least one helical strip revolves around thelongitudinal axis and cuts or abrades the cartilage.

In some embodiments, a cartilage removal tool comprises a handle havinga longitudinal axis and a distal end. A cartilage removal portion is atthe distal end of the handle. The cartilage removal portion has a curvedplate with a plurality of serrated blades thereon. Each serrated bladeis substantially perpendicular to a major surface of the curved plate.Each serrated blade has a plurality of teeth substantially perpendicularto the major surface. Each serrated blade is adapted for removingmaterial.

In some embodiments, a method of removing cartilage comprises contactinga cartilage with a tool comprising a handle having a longitudinal axisand a trapezoidal tube at an end of the handle. The trapezoidal tube hasinner walls defining an opening therethrough. The opening has an axissubstantially parallel to the longitudinal axis of the handle. Thetrapezoidal tube has at least one cutting edge. The tool is moved, so asto cut or grind the cartilage.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is an isometric view of an embodiment of a cartilage removalinstrument.

FIG. 1B is a side cross sectional view of one of the blades of thecartilage removal instrument of FIG. 1A.

FIG. 1C is an enlarged detail of one of the teeth of FIG. 1A.

FIG. 1D shows a variation of the arrangement of FIG. 1C, in which theteeth are staggered between adjacent blades.

FIG. 2 is a front view of a cartilage removal instrument having anelongated member for cartilage removal.

FIG. 3 is a front view of a cartilage removal instrument having twoelongated members for cartilage removal.

FIG. 4 is a front view of a cartilage removal instrument having fourelongated members for cartilage removal.

FIG. 5A is a front view of a cartilage removal instrument having eightelongated members for cartilage removal.

FIG. 5B is an end view of the cartilage removal instrument of FIG. 5A.

FIG. 6 is a side view of a cartilage removal instrument having a pair ofhelical cutting strips.

FIG. 7 is a top view of a cartilage removal instrument having aplurality of grating features.

FIG. 8 is an isometric view of another cartilage removal instrumenthaving a plurality of grating features.

FIG. 9 is an enlarged detail of the grater of FIG. 8.

FIG. 10 is an exploded view of the cartilage removal instrument of FIG.8.

FIG. 11 is an isometric view of a cartilage removal tool having convexand concave sides.

FIGS. 12 and 13 show an embodiment of a tool having a trapezoidal tubewith a cutting edge.

DETAILED DESCRIPTION

This description of the exemplary embodiments is intended to be read inconnection with the accompanying drawings, which are to be consideredpart of the entire written description. In the description, relativeterms such as “lower,” “upper,” “horizontal,” “vertical,”, “above,”“below,” “up,” “down,” “top” and “bottom” as well as derivatives thereof(e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should beconstrued to refer to the orientation as then described or as shown inthe drawing under discussion. These relative terms are for convenienceof description and do not require that the apparatus be constructed oroperated in a particular orientation. Terms concerning attachments,couplings and the like, such as “connected” and “interconnected,” referto a relationship wherein structures are secured or attached to oneanother either directly or indirectly through intervening structures, aswell as both movable or rigid attachments or relationships, unlessexpressly described otherwise.

This disclosure provides embodiments of a cartilage removal toolsuitable for minimally invasive surgery. Various embodiments can beoperated by hand, or by attaching the cartilage removal tool to apowered driver instrument for reciprocal or rotational motion.

Any of the embodiments described below can comprise stainless steel ortitanium, for example.

FIGS. 1A-1C show an instrument 100 for use in cartilage removal. FIG. 1Ais an isometric view of the instrument 100. The instrument 100 comprisesan elongate body 102 having a first end 103 and a longitudinal axis A.The instrument 100 has a cartilage removal portion 104 coupled to theelongate body 102 at the first end 103. The cartilage removal portion104 includes a plurality of serrated circular blades 110 a-110 i.Although FIG. 1A shows nine blades 110 a-110 i, other embodiments canhave any number of blades. Each serrated circular blade 110 a-110 i hasa centroid thereof located along the longitudinal axis A.

Each of the serrated circular blades 110 a-110 i has a plurality ofteeth 112 arranged around a respective circumference of the blade. Theserrated circular blades 110 a-110 i are substantially perpendicular(i.e., at an angle from 60 degrees to 120 degrees) to the longitudinalaxis and adapted for removing material while moving in the longitudinaldirection of the longitudinal axis. FIG. 1B is a cross-sectional view ofone of the circular blades 110 a. FIG. 1C is a front view of one of theteeth 112. In some embodiments, each of the serrated circular blades 110a-110 i has a same number of teeth 112. In FIG. 1A, the serratedcircular blades 110 a-110 i are aligned so that each tooth 112 of afirst one of the serrated circular blades 110 a lies along a respectiveline segment (e.g., 105 and 107) parallel to the longitudinal axis A.Each respective line segment 105, 107 passes through a respective tooth112 of a second one of the serrated circular blades 110 b. Theinstrument 100 is rotationally symmetric about the axis A. In otherembodiments (not shown) a given circular blade may be rotationallyoffset from an adjacent circular blade on one or both sides thereof.

In some embodiments, each of the teeth 112 has a first face 117 a and asecond face 117 b, with a respective bevel 113, 115 on an edge of atleast one of the first or second faces. In some embodiments, as shown inFIG. 1B, each of the teeth 112 has a first face and a second face, witha respective bevel 113, 115 on respective edges of both the first andsecond faces. In some embodiments, each of the plurality of teeth 112has a substantially flat tip 14 at the outer radial edge of the tooth.As shown in FIG. 1C, each serrated circular blade 110 a-110 i, caninclude a curved concavity 116 between each pair of adjacent teeth 112.In other embodiments (not shown), each concavity can have two flat,planar edges.

FIG. 1D shows a variation of the embodiment of FIG. 1C, in which theserrated circular blades 114 and 124 are rotationally staggered, so thatthe teeth 124 of a second blade 122 are aligned with the curvedconcavity 116 of the first blade 112. Having the cutting edges 114 and124 staggered may help with removing cartilage on asymmetric joints.

In some embodiments, as shown in FIG. 1A, the distal end 109 of theinstrument 100 has a curved shape, such as a portion of a spheroid,ellipsoid, or paraboloid. The curved distal end helps avoid damage totissue which the distal end 109 contacts.

FIG. 1B shows dashed lines at the boundary between a first serratedcircular blade 110 a and an adjacent serrated circular blade 110 b. Insome embodiments, the instrument 100 is formed of a single piece ofmaterial (e.g., by an additive manufacturing process or sintering orturning/milling), and the dashed lines 117 a, 117 b correspond to animaginary boundary between two portions 110 a, 110 b of the same unitaryinstrument 100. In other embodiments, each of the serrated circularblades 110 a-110 i is formed separately, and has faces 117 a, 117 b. Theindividual blades 110 a-110 i are joined together by, for example,adhesive, soldering, or by running a fastener (e.g., a threaded end ofthe elongated member 102) through a threaded center bore (not shown) ineach serrated circular blade 110 a-110 i.

In some embodiments, the method of using the instrument 100 includesmaking a small incision over the metatarsophalangeal (MTP) joint (thejoint between the metatarsal bones of the foot and the proximal bones,phalanges, of the toes). The surgeon uses a distractor to expand thejoint space to allow enough room for the cartilage removal instrument100 to be placed in the joint space (between metatarsal head and phalanxhead). The surgeon inserts the instrument 100 through a cannula into anincision in a patient's skin, and inserting the cartilage removalportion 104 into the vicinity of a joint, so one or more of the teeth112 contact the cartilage. The instrument 100 can be moved with areciprocating motion while contacting the cartilage, to cut or grind thecartilage. The instrument 100 can be moved with a reciprocating motionand rotating motion simultaneously while contacting the cartilage, tocut or grind the cartilage. The instrument 100 can be manipulatedmanually, or the instrument can be driven by a reciprocating tool (suchas a reciprocating saw). The surgeon then begins compressing the jointusing a distractor, and continues with the procedure/fusion.

In some embodiments, the instrument 100 has a cannula 150, as shown inFIG. 1A. The user can couple the cannula 150 with an irrigation source(not shown), a light source (not shown), and/or an optical sensorcoupled to a transmission medium (e.g., optical fiber or cable),allowing the surgeon to ensure that all cartilage has been removed andflushed from the joint space. In other embodiments (not shown), thecannula 150 can be omitted.

Although FIG. 1A shows an instrument 100 with a cylindrical elongatedmember 102, a drill shank can be substituted for part or all of theelongated member 102, so the instrument is adapted for use with anydrill chuck or reciprocating tool chuck.

In FIGS. 1A, the blades 110 a-110 i all have the same size as eachother, giving the cartilage removal portion 104 of instrument 100 anapproximately cylindrical configuration. In other embodiments (notshown), the cartilage removal portion 104 may have other shapes, such asan egg-shaped or hourglass-shaped portion, to better conform to jointsurfaces. That is, the serrated circular blades can have varying sizesto fit within an egg-shaped envelope or an hourglass-shaped envelope.

FIGS. 2-5 show embodiments of a cartilage removal instrument 200, 300,400, 500 configured for use with a rotating motion.

FIG. 2 shows a cartilage removal instrument 200 having a shank 210 and acartilage removal portion 204. In some embodiments, the shank 210 is adrill shank having a flat surface 214. In some embodiments, the shank210 has a quick release connector 212 (e.g., an AO style quick connectshaft) adapted to be received by a tool (not shown) with a correspondingquick-release socket (not shown).

The cartilage removal portion 204 has a first hub 216 at a first end 231of the cartilage removal portion 204 and a second hub 240 at a secondend 232 of the cartilage removal portion 204. A central member 220extends from the first hub 216 to the second hub 240. The first hub 216and the second hub 240 are fixed to the elongated member 220 forrotation together about a longitudinal axis B. In the embodiment of FIG.2, the shank 210, the first hub 216, the second hub 240 and the centralmember 220 all share the same longitudinal axis B.

The cartilage removal portion 204 includes one or more elongate members230 disposed radially outward from the longitudinal axis B. The one ormore elongate members 230 extend parallel to the longitudinal axis Bfrom the first end 231 to the second end 232. In some embodiments theelongated member 230 has a circular cross-section. In other embodiments,the elongated member 230 has a flat rectangular cross section, with theshorter dimension of the rectangular cross section oriented in theradial direction e_(r) of the instrument 200 (and the longer dimensionof the rectangle in the tangential direction e_(⊖)). In someembodiments, the elongated member 230 has a flat cross section with atleast one sharpened edge oriented in the tangential direction e_(⊖), toenhance slicing action when the instrument 200 rotates about the axis B.In some embodiments, the circumferential surface 230 s of elongatedmember 230 (having a surface normal in the radial direction e_(r)) isrough or textured for removing cartilage by shearing. For example, thesurface 230 s can have a rough diamond coating.

The instrument 200 in FIG. 2 has a shank 210 with a flat or keyedsurface 214 and has a mount 212 adapted to be gripped by a quick connectsocket of a motorized tool (not shown). In other embodiments, a varietyof shafts or shanks can be substituted for the shank 210.

In some embodiments, the method of using the instrument 100 includesmaking a small incision over the MTP joint. The surgeon uses adistractor to expand the joint space to allow enough room for thecartilage removal instrument 200 to be placed in the joint space(between metatarsal head and phalanx head). The surgeon inserts theinstrument 200 through a cannula into an incision in a patient's skin,and inserts the cartilage removal portion 204 into the vicinity of ajoint. The shank 210 is rotated, for example, manually or by using asurgical drill having a socket to which the shank 210 is connected. Thedrill causes the central member 220 and elongate member 230 to rotatearound the longitudinal axis B, so that the one or more elongate member230 cut or abrade the cartilage. The surgeon then begins compressing thejoint using a distractor, and continues with the procedure/fusion.

In some embodiments, the instrument 200 has a cannula 250, as shown inFIG. 2. The user can couple the cannula 250 with an irrigation source(not shown), a light source (not shown), and/or an optical sensorcoupled to a transmission medium (e.g., optical fiber or cable),allowing the surgeon to ensure that all cartilage has been removed andflushed from the joint space. In other embodiments (not shown), thecannula 250 can be omitted.

In some embodiments, the outer circumferential surface 230 s of theelongated member is rough or textured, and cartilage can be abraded orground by rotating or reciprocating the instrument 200.

FIG. 3 shows a cartilage removal instrument 300, which is a variation ofthe instrument 200 of FIG. 2. The shank 310, quick connect 312, flatsurface 314, first hub 316, central member 320, first end 331, secondend 332 and second hub 340 can be the same as the shank 210, quickconnect 212, flat surface 214, first hub 216, central member 220, firstend 231, second end 232, and second hub 240, respectively, describedabove. For brevity, descriptions of these common elements are notrepeated. The method of using the cartilage removal instrument 300 canalso be the same as the method of using the cartilage removal instrument200 described above, and, solely for brevity, the description of use isnot repeated.

In some embodiments, the cartilage removal instrument 300 has twoelongated members 330 a, 330 b. In some embodiments, the elongatedmembers are spaced 180° apart, on opposite sides of the central member320, to better balance the distribution of mass of the elongated members330 a, 330 b around the longitudinal axis C. When the instrument 300 isrotated, the balanced mass may reduce or prevent wobble and/orvibration, for smoother cartilage removal.

In some embodiments, the instrument 300 has a cannula 350, as shown inFIG. 3, which can be used as discussed above with respect to cannula 150in FIG. 1A. In other embodiments (not shown), the cannula 350 can beomitted.

FIG. 4 shows a cartilage removal instrument 400, which is a variation ofthe instrument 200 of FIG. 2. The shank 410, quick connect 412, flatsurface 414, first hub 416, first end 421, can be the same as the shank210, quick connect 212, flat surface 214, first hub 216, first end 231,respectively, described above. For brevity, descriptions of these commonelements are not repeated. The method of using the cartilage removalinstrument 400 can also be the same as the method of using the cartilageremoval instrument 200 described above, and, solely for brevity, thedescription of use is not repeated.

In some embodiments, the cartilage removal instrument 400 has fourelongated members 430, 431, 432, and a fourth elongated member (notshown) evenly spaced 90° apart, to better balance the distribution ofmass of the elongated members 430, 431, 432, . . . around thelongitudinal axis D. (The fourth member is positioned spaced 180° apartfrom elongated member 431.) When the instrument 400 is rotated, thebalanced mass may reduce or prevent wobble and/or vibration, forsmoother cartilage removal.

The cartilage removal instrument 400 can omit a second hub at the secondend 422. In some embodiments, each elongated member (e.g., 430, 432) hasa respective radial portion (e.g., 430 e, 432 e) extending from thecentral longitudinal axis D to the end of the respective elongatedmember 430, 432, . . . . The radial portions 430 e, 432 e, . . . can beattached to each other (e.g., by welding or soldering) at theirintersection along the longitudinal axis D. In other embodiments (notshown), an instrument has a second hub at the second end 422, to whichthe four elongated members 430, 431, . . . are attached. In someembodiments, the outer end surface of the radial portions 430 e, 432 e,. . . can be rough or textured, and can be held against cartilage whilerotating the shank or shaft 410, to remove material.

FIGS. 5A-5B show a cartilage removal instrument 500, which is avariation of the instrument 400 of FIG. 4. FIG. 5A is a side view of thecartilage removal instrument 500, and FIG. 5B is front view. The shank510, quick connect 512, flat surface 514, and first hub 516, can be thesame as the shank 410, quick connect 412, flat surface 414, first hub416, respectively, described above. For brevity, descriptions of thesecommon elements are not repeated. The method of using the cartilageremoval instrument 500 can also be the same as the method of using thecartilage removal instrument 200 described above, and, solely forbrevity, the description of use is not repeated.

In some embodiments, the cartilage removal instrument 500 has eightelongated members 530, 531, 532, . . . evenly spaced 45° apart, tobetter balance the distribution of mass of the elongated members 530,531, 532, . . . around the longitudinal axis E. When the instrument 500is rotated, the balanced mass may reduce or prevent wobble and/orvibration, for smoother cartilage removal. In other embodiments, theeight elongated members 530, 531, 532, . . . may all be included in asingle continuous wire having a plurality of bends (not shown), embeddedwithin the first hub 516.

The cartilage removal instrument 500 can omit a second hub at the secondend 522. In some embodiments, the elongated members (e.g., 530, 532 . .. ) are arranged in pairs, and the elongated members within each pairare connected to each other by a perpendicular member at the second end522 of the instrument 500. FIG. 5B shows an arrangement in which,proceeding counterclockwise from a first elongated member at the 3o'clock position, the pairs include the first and fifth elongatedmembers (connected by member 541), the second and eighth elongatedmembers (connected by member 542), the third and seventh elongatedmembers (connected by member 543), and the fourth and sixth elongatedmembers (connected by member 544). The end portions 541, 542, . . . canbe attached to their respective elongated members (e.g., by welding orsoldering) at the second end 522 of the cartilage removal instrument500. Alternatively, the end portions 541, 542, . . . can be formed fromthe same wire as their respective elongated members. In otherembodiments (not shown the instrument has a second hub at the second end522, to which the eight elongated members 530, 531, . . . are attached.

The cartilage removal instruments 200, 300, 400 and 500 can shave offcartilage while not damaging bone in the region.

FIG. 6 shows a cartilage removal instrument 700, which is a variation ofthe instrument 200 of FIG. 2. The shank 710, quick connect 712, flatsurface 714, first hub 716, central member 720, first end 721, secondend 722 and second hub 740 can be the same as the shank 210, quickconnect 212, flat surface 214, first hub 216, central member 220, firstend 231, second end 232, and second hub 240, respectively, describedabove. For brevity, descriptions of these common elements are notrepeated. The method of using the cartilage removal instrument 700 canalso be the same as the method of using the cartilage removal instrument200 described above, and, solely for brevity, the description of use isnot repeated.

In some embodiments, the cartilage removal instrument 700 has twoelongated helical strips 730, 731 separated radially from thelongitudinal axis G by an annular space 725. Because of the annularspace 725, the helical strips 730, 731 have continuous helical cuttingedges facing in a direction e_(c) orthogonal to the radial direction).In some embodiments, the elongated strips 730, 731 are phased 180°apart, on opposite sides of the central member 720, to better balancethe distribution of mass of the helical strips 730, 731 around thelongitudinal axis G; the annular space 725 is located radially betweenthe central member 720 and the helical strips 730, 731. When theinstrument 700 is rotated, the leading edge of each helical strips 730,731 contacts and cuts or abrades the cartilage.

In some embodiments, each elongated helical strips 730, 731 has a flatrectangular cross section, with the shorter dimension of the rectangularcross section oriented in the radial direction e_(r) of the instrument200 (and the longer dimension of the rectangle in the tangentialdirection e_(⊖)). In some embodiments, the elongated helical strips 730,731 have a flat cross section with at least one sharpened edge orientedin the tangential direction e_(⊖), to enhance slicing action when theinstrument 700 rotates about the axis G. In some embodiments, thecircumferential surface 730 s, 731 s of elongated helical strips 730,731 (having a surface normal in the radial direction e_(r)) is rough ortextured for removing cartilage by shearing.

The helical strips 730, 731 can be used to shave off the cartilage. Theangled cutting edge of each helical strip aids in directing cartilageaway from the site once the cartilage has been removed, to preventclogging of the instrument 700. The helical strips 730, 731 may be dullor curved inward (to only remove cartilage), or sharp (to aid in slightremoval of bone to expose an appropriate amount of healthy, bleedingbone to aid in fusion).

In some embodiments, the instrument 700 has a cannula 750, as shown inFIG. 6, which can be used as discussed above with respect to cannula 150in FIG. 1A. In other embodiments (not shown), the cannula 750 can beomitted.

FIG. 7 is a side view of an embodiment of a cartilage removal device inthe form of a grater 600 suitable for a grating or abrasion action. Thegrater 600 has a shank 610 and a cartilage removal portion 604 attachedto the shank 610. The cartilage removal portion 604 includes a plate 620having a first face 622 and a second face 624 opposite the first face622.

The plate 620 defines one or more holes 630 extending through the plate620 from the first face 622 to the second face 624. The rows of holes630 can be arranged staggered, as shown in FIG. 7, so that each row isoffset from the preceding and/or succeeding row by half the pitchbetween adjacent holes within a row. In other embodiments (not shown),the rows and columns of holes 630 are aligned in a rectangular grid,without any offset between adjacent holes within the same column.

Each hole 630 is defined by a respective cutting edge of the plate. Insome embodiments, the plate 620 has a respective scallop-shaped scoop631 adjacent each respective hole 630 in the array of holes. When theplate moves or reciprocates in the direction of longitudinal axis F, thescallop-shaped scoops 631 and the edges surrounding the holes 630 cut orabrade the cartilage, and the scallop-shaped scoops deflect the cut orabraded cartilage into their respective holes. The scallop-shaped scoops631 may be dull (to only remove cartilage), or sharp (to aid in removalof a small amount of bone, to expose an appropriate amount of healthy,bleeding bone to aid in fusion).

In some embodiments, the plate includes a concave indentation 632adjacent each hole 630, so that the hole 630 is between a respectiveindentation 632 and scallop-shaped scoop 631. The indentation 632 allowsthe cartilage to extend below the surface 622 of the plate 620 (i.e.,into the page of FIG. 7), so the hole 630 and scallop-shaped scoop 631slice or abrade more deeply into the cartilage.

In operation, the instrument 600 is used by inserting the instrument 600through a cannula (not shown) into an incision in the patient's skin,and inserting the cartilage removal portion 604 into the vicinity of ajoint. The instrument 600 is positioned so the cartilage removal portion604 contacts the cartilage of the patient. The shank 610 isreciprocated, for example using a reciprocating tool having a socket towhich the quick connect 612 of shank 610 is connected. The reciprocatingtool causes the cartilage removal portion 604 to move back and forth ina direction parallel to the longitudinal axis F, so that the cuttingedges defining one or more holes 630 and the respective scallop-shapedscoops 631 slice or abrade the cartilage. In other embodiments of themethod, the surgeon can manually reciprocate the instrument 600 withoutusing a motorized tool.

In some embodiments, the instrument 600 has a cannula 650, as shown inFIG. 7, which can be used as discussed above with respect to cannula 150in FIG. 1A. In other embodiments (not shown), the cannula 650 can beomitted.

FIGS. 8-10 show an instrument 900, which is a variation of theinstrument 600 of FIG. 7. FIG. 8 is an isometric drawing of theinstrument 900. FIG. 9 is an enlarged detail of the cartilage removalportion 904 of FIG. 8. FIG. 10 is an exploded view of the instrument900. The instrument 900 has a shank 910 and a grater 904. The grater 904is attached to the shank 910. The grater 904 has a plate 920 having afirst face 920 a and a second face 920 b opposite the first face 920 a.The plate 920 defines one or more holes 930 extending therethrough fromthe first face 920 a to the second face 920 b. Each hole 930 is definedby a respective cutting edge of the plate 920 surrounding the hole 930.

The plate 920 includes at least a first blade 932 and a second blade934. The first and second blades 932, 934 are substantiallyperpendicular (i.e., at an angle from 60 degrees to 120 degrees) to alongitudinal axis H of the shank 910 and adapted for removing materialwhile moving in the longitudinal direction of the longitudinal axis. Atleast one of the one or more holes 930 are located at a center of thefirst blade 932, separating the first blade 932 into two blade portions.The second blade 934 is parallel to the first blade 932 and adjacent tothe at least one hole 930. The second blade 934 is configured to deflectcartilage into the at least one hole 930 during the reciprocating. Forexample, as shown in FIG. 9, the second blade 934 is sloped toward thehole 930. When the instrument 900 contacts cartilage and is moved in thedirection of axis H so that the hole 930 reaches a given point on thecartilage before the blade 934 reaches that same point, blade 934scrapes cartilage and deflects the cartilage toward the hole 930. In thesame way, each of the holes 930 is adjacent a respective blade that candeflect cartilage toward that respective hole 930.

The method of using the instrument 900 includes contacting a cartilageof a patient with the grater 904. The grater 904 has a shank 910attached to a plate 920. The plate 920 has a first face 920 a and asecond face 920 b opposite the first face 920 a. The plate 920 definesone or more holes 930 extending therethrough from the first face 920 ato the second face 920 b, where each hole 930 is defined by a respectivecutting edge of the plate 920. In some embodiments, a reciprocating toolis used to reciprocate the plate 920 so that the respective cutting edge934 defining one or more of the holes 930 cuts or abrades the cartilage.

The instrument 900 includes a type of shank 910 that can be connected toa reciprocating tool. The shank 910 of the instrument 900 has a ball 912extending part way through a circular opening 914 in a housing 916. Theattachment portion 940 has a cross-shaped end 942 that is adapted to bereceived in mating slots 918 of the housing 916. The attachment portion940 retains the ball 912 within the housing, while allowing angularrotations α and β (shown in FIG. 8) of the shank 910 in two orthogonaldirections. The ball mount allows the reciprocating tool to be orientedat an angle relative to the longitudinal axis H of the shank 910, toaccess hard-to-reach joints.

FIG. 10 is an exploded view of the instrument 900. The shank 910 has amounting plate 922 at the end opposite the attachment portion 940. Theplate 920 can be attached to the mounting plate 922 by a screw 924,rivet, or the like inserted through the hole 923 in the mounting plate922. In some embodiments, the plate 920 is used for one surgicalprocedure, removed, and replaced with a fresh plate 920. The attachmentportion 940 can be secured to the housing 916 by set screws 925 or otherfasteners.

FIG. 11 shows another embodiment of a cartilage removal tool 800. Thetool 800 has a handle or shank 810 having a longitudinal axis F and adistal end. A cartilage removal portion 820 is attached at the distalend of the handle or shank 810. The cartilage removal portion 820 has acurved plate 821. In some embodiments, the plate 821 of the cartilageremoval portion 820 has a curvature in two perpendicular directions. Thecurvature in the first direction is shown by the angle of curvature ⊖ ina plane containing the longitudinal axis F. The curvature in the seconddirection is shown by the angle of curvature ϕ in a plane orthogonal tothe longitudinal axis F. The curved plate 821 has a convex side 821 aand a concave side 821 b. In some embodiments, the convex side is convexin the directions of both ⊖ and ϕ, and the concave side 821 b is concavein the directions of both ⊖ and ϕ. In other embodiments (not shown), theplate 821 is curved in the plane of the angle ⊖, but the angle ϕ iszero. In another embodiments (not shown), the plate 821 is curved in theplane of the angle ϕ, but the angle ⊖ is zero.

The curved plate 821 has a plurality of serrated blades 822 a-822 g, 823a-823 g thereon. Each serrated blade 822 a-822 g, 823 a-823 g has aplurality of teeth 824. Each tooth 824 has a ramped surface increasingin height H from a distal end of the tooth 824 to a proximal end of thetooth 824. Within each blade 822 a-822 g, 823 a-823 g, each pair ofadjacent teeth 824 has a concave surface 825 between the pair ofadjacent teeth 824.

Each serrated blade 822 a-822 g, 823 a-823 g is substantiallyperpendicular to the longitudinal axis F of the handle or shank 810. Forexample, in FIG. 11, each blade 822 a-822 g is substantiallyperpendicular (e.g., from 60 degrees to 120 degrees) to the convexsurface 821 a, and each blade 823 a-823 g is substantially perpendicularto the concave surface 821 b. In FIG. 11, since the plate 821 is curvedin the plane of the angle ϕ, and the surface 821 a is convex in theplane of the angle ϕ, each blade 822 a-822 g has a curvature in theplane of the angle ϕ. For example, in FIG. 11, the exemplary range of ⊖can be in a range from 0 degrees to 45 degrees, and in some embodiments,can be a range from 10 degrees to 30 degrees, and in some embodiments,in a range from 20 degrees to 30 degrees. Also, in FIG. 11, theexemplary range of ϕ can be from 0 degrees to 30 degrees, and in someembodiments, can be a range from 5 degrees to 20 degrees, and in someembodiments, in a range from 10 degrees to 15 degrees. The base and thecutting edge of each blade 822 a-822 g, 823 a-823 g are curved in theplane of the angle ϕ by the same angle as the corresponding convex andconcave surfaces 821 a and 821 b.

In some embodiments, the serrated blades 822 a-822 g, 823 a-823 g have aplurality of different heights. In some embodiments, the height H of theserrated blades 822 a-822 g on the convex side 821 a can have a firstheight value at or near the proximal end or the distal end of thecartilage removal portion 820 and at least one second height valuebetween the proximal end and the distal end of the cartilage removalportion 820, where the second height is greater than the first height.In some embodiments, the serrated blades 823 a-823 g on the concave side821 b have a third height value at or near the proximal end or thedistal end of the cartilage removal portion and at least one fourthheight value between the proximal end and the distal end of thecartilage removal portion, where the fourth height is less than thethird height.

For example, in FIG. 11, the heights increase from blade 822 a to 822 d,and then decrease from blade 822 d to 822 g; the heights decrease fromblade 823 a to 823 d, and then increase from blade 823 d to 823 g. Thus,the cutting edges of the blades 822 a-822 g lie along a convex envelope,which may be an ellipsoid, paraboloid, ovoid or the like. Similarly, thecutting edges of the blades 823 a-823 g lie along a concave envelope,which may be an ellipsoid, paraboloid, ovoid or the like. The blades onthe convex side 821 a or the concave side 821 b are adapted to removematerial when the instrument 800 is moved in the direction of the convexside 821 a or the concave side 821 b, respectively. In thisconfiguration, the side of the cartilage removal corresponding to theconvex side 821 a of plate 821 is adapted for removing cartilage fromconcave surfaces, and the side of the cartilage removal corresponding tothe concave side 821 b of plate 821 is adapted for removing cartilagefrom convex surfaces.

In operation, the instrument 800 can be oscillated manually or byattachment to a reciprocating tool. The combination of curved, concaveand convex sides can remove cartilage and aid in removal of thin layersof bone to expose an appropriate amount of healthy, bleeding bone to aidin fusion. The curved concave/convex shape of instrument 800 can be usedfor the cup/cone joint prep for joint fusion.

FIGS. 12 and 13 show a tool 1000 used in another method of removingcartilage.

The tool 1000 comprises a handle or shank 1010 having a longitudinalaxis J and a substantially isosceles trapezoid shaped tube 1030 at anend of the handle or shank 1010. The trapezoidal tube 1030 has innerwalls 1031 defining an opening 1025 therethrough. The opening 1025 hasan axis K substantially parallel to the longitudinal axis J of thehandle or shank 1010. The trapezoidal tube 1030 has at least one cuttingedge 1021, 1023. For example, the tube 1030 can have a proximal cuttingedge 1021 and a distal cutting edge 1023. In some embodiments, thelateral sides 1027 and 1028 of the isosceles trapezoid shaped tube 1030have additional cutting edges. In some embodiments, the outer surface1029 can be rough or textured for fine abrasion and removal of thinlayers of remaining cartilage.

In operation, the surgeon contacts a cartilage with the tool 1000. Thesurgeon can use the cutting edge 1021 to manually cut the cartilagewhile withdrawing the tool 1000 from the joint. Alternatively, thesurgeon can manually reciprocate the tool 1000, so as to cut thecartilage with both the edges 1021 and 1023. For fine adjustments, thesurgeon can contact the cartilage with the outer surface 1029 andmanually reciprocate the tool 1000 to remove a thin layer of cartilage.

Although the subject matter has been described in terms of exemplaryembodiments, it is not limited thereto. Rather, the appended claimsshould be construed broadly, to include other variants and embodiments,which may be made by those skilled in the art.

What is claimed is:
 1. An instrument for use in cartilage removal, the instrument comprising: an elongate body having a first end and a longitudinal axis having a longitudinal direction; and, a cartilage removal portion coupled to the elongate body at the first end, the cartilage removal portion including a plurality of serrated blades substantially perpendicular to the longitudinal axis and adapted for removing material while moving in the longitudinal direction, each serrated blade having a centroid thereof located along the longitudinal axis.
 2. The instrument of claim 1, wherein each of the blades has a circular plate with a plurality of teeth arranged around a respective circumference.
 3. The instrument of claim 2, wherein: the serrated blades are aligned so that each tooth of a first one of the serrated blades lies along a respective line segment parallel to the longitudinal axis, and each respective line segment passes through a respective tooth of a second one of the serrated blades.
 4. The instrument of claim 2, wherein each of the serrated circular blades has a same number of teeth.
 5. The instrument of claim 2, wherein each of the plurality of teeth has a first face and a second face, with a respective bevel on an edge of at least one of the first or second faces.
 6. The instrument of claim 2, wherein each of the plurality of teeth has a first face and a second face, with a respective bevel on respective edges of the first and second faces.
 7. The instrument of claim 2, wherein each of the plurality of teeth has a substantially flat tip.
 8. A method for cartilage removal, comprising: contacting a cartilage of a patient with a cartilage removal portion of a tool, the cartilage removal portion having a first end, a second end, and a longitudinal axis extending therebetween, the cartilage removal portion including one or more elongate members disposed radially outward from the longitudinal axis, wherein the one or more elongate members extend parallel to the longitudinal axis from the first end to the second end; and causing the elongate body to rotate around the longitudinal axis or reciprocate, so that the one or more elongate extensions cut or abrade the cartilage.
 9. A method for cartilage removal, comprising: contacting a cartilage of a patient with a grater, the grater having a shank attached to a plate, the plate having a first face and a second face opposite the first face, the plate defining one or more holes extending therethrough from the first face to the second face, each hole defined by a respective cutting edge of the plate; and reciprocating the plate so that the respective cutting edge defining one or more of the holes cuts or abrades the cartilage.
 10. The method of claim 9, wherein: the plate has a respective scoop adjacent each respective hole in the array of holes, and the reciprocating includes deflecting cartilage through one of the holes by the respective scoop thereof.
 11. The method of claim 9, wherein: the plate includes at least a first blade and a second blade, the first and second blades being perpendicular to a longitudinal axis of the handle, at least one of the one or more holes located at a center of the first blade, separating the first blade into two blade portions, and the second blade is parallel to the first blade and adjacent to the at least one hole, where the second blade is configured to deflect cartilage into the at least one hole during the reciprocating.
 12. A method for cartilage removal, comprising: contacting a cartilage of a patient with a cartilage removal tool having a central longitudinal axis, and at least one rotatable helical strip arranged around the longitudinal axis, the helical strip separated radially from the longitudinal axis by a space; and, rotating the at least one helical strip so that the at least one helical strip revolves around the longitudinal axis and cuts or abrades the cartilage.
 13. The method of claim 12, wherein the at least one helical strip includes a first helical strip and a second helical strip, the first helical strip and the second helical strip coupled to the elongated member and arranged on opposite sides of the longitudinal axis.
 14. A cartilage removal tool, comprising: a handle having a longitudinal axis and a distal end; and a cartilage removal portion at the distal end of the handle, the cartilage removal portion having a curved plate with a plurality of serrated blades thereon, each serrated blade substantially perpendicular to a major surface of the curved plate, each serrated blade having a plurality of teeth substantially perpendicular to the major surface, each serrated blade adapted for removing material.
 15. The cartilage removal tool of claim 14, wherein each tooth has a ramped surface increasing in height from a distal end thereof to a proximal end thereof.
 16. The cartilage removal tool of claim 14, wherein the serrated blades have a plurality of different heights.
 17. The cartilage removal tool of claim 16, wherein: the curved plate has a convex side including at least some of the plurality of serrated blades thereon, and the serrated blades on the convex side have a first height at or near the proximal end or the distal end of the cartilage removal portion and at least one second height between the proximal end and the distal end of the cartilage removal portion, where the second height is greater than the first height.
 18. The cartilage removal tool of claim 17, wherein: the curved plate has a concave side including at least some of the plurality of serrated blades thereon, and the serrated blades on the concave side have a third height at or near the proximal end or the distal end of the cartilage removal portion and at least one fourth height between the proximal end and the distal end of the cartilage removal portion, where the fourth height is less than the third height.
 19. The cartilage removal tool of claim 14, wherein the cartilage removal portion has a curvature in two perpendicular directions.
 20. The cartilage removal tool of claim 14, wherein each serrated blade is configured to remove material while the cartilage removal tool is moving in a direction of the major surface.
 21. A method of removing cartilage, comprising: contacting a cartilage with a tool comprising a handle having a longitudinal axis and a trapezoidal tube at an end of the handle, the trapezoidal tube having inner walls defining an opening therethrough, the opening having an axis substantially parallel to the longitudinal axis of the handle, the trapezoidal tube having at least one cutting edge; and moving the tool, so as to cut or grind the cartilage.
 22. The method of claim 21, wherein moving the tool comprises moving the tool in a direction of the longitudinal axis, or in a direction perpendicular to the longitudinal axis.
 23. The method of claim 21, wherein moving the tool comprises rotating the tool around the longitudinal axis. 